Search PubMed⌕ Search

Biomedical subjects

N Josso

Publications and source records attributed to N Josso.

At least 109 records · Page 6Linked to original sources
PubMed1981

[Purification of bovine antimullerian hormone using a monoclonal antibody].

Bovine antimüllerian hormone (AMH) has been purified from incubation medium of bovine fetal testes, by immunoaffinity chromatography using a monoclonal antibody. Presence of AMH in the column eluate is demonstrated by its high antimüllerian activity. Biochemical analysis, by SDS polyacrylamide gel electrophoresis, indicates that the testicular protein eluted from the column co-electrophoreses with native tritiated AMH which, as previously shown, is a dimer of 124,000 +/- 15,000 MW.

Animals↗
PubMed1981

Anti-Müllerian hormone: a local or long-distance morphogenetic factor?

In an attempt to determine whether anti-Müllerian hormone could exert long-distance effects, we studied the anti-Müllerian activity of gonads from bovine Freemartin fetuses. Anti-Müllerian activity was detected in 3 out of the 7 animals studied: one was 62 days old, and its gonad contained undifferentiated tissue only; the 2 others were 110 and 130 days old respectively, and their gonads contained seminiferous tubules. The gonads devoid of anti-Müllerian activity contained only rete tubules or fibrous tissue. Anti-Müllerian activity was absent in fetal male and Freemartin serum, except in 2 cases, in which low activity was present after 37-fold purification by lectin affinity chromatography. The presence of anti-Müllerian activity in Freemartin gonads with seminiferous tubules is an indication that gonadal virilization in these fetuses is functional as well as morphological. Further experiments are needed to determine whether regression of the Müllerian ducts in the Freemartin is due to anti-Müllerian hormone produced by the Freemartin gonads in situ.

Animals↗
PubMed1980

Embryonic testicular regression syndrome: variable phenotypic expression in siblings.

Two 46,XY agonadal siblings with variable degrees of sexual ambiguity are described. The eldest child is a phenotypic male with micropenis. The younger patient, a phenotypic female with slight fusion of the genital folds and absent müllerian ducts, conforms to the criteria usually accepted for the diagnosis of true agonadism. Coexistence of anorchia and true agonadism in the same sibship supports the hypothesis, suggested by others, that both disorders are related and are due to the regression of the embryonic testes.

Child↗
PubMed1979

Detection of anti-Müllerian activity in boar rete testis fluid.

Boar rete testis fluid was tested for its capacity to induce Müllerian regression in 14.5-day-old rat Müllerian ducts. Weak activity was present in crude RTF, but after gel filtration 5-fold concentration, greater activity was detected in 1 our of 7 pools of the eluted fractions. The biologically active fraction (mol. wt 160 000-310 000) coincided with the elution of authentic labelled anti-Müllerian hormone, obtained from bovine fetal testes. These results indicate that a small amount of anti-Müllerian hormone is still synthesized in post-natal life.

Animals↗
PubMed1978

Biosynthesis of labelled anti-müllerian hormone by fetal testes: evidence for the glycoprotein nature of the hormone and for its disulfide-bonded structure.

Tritiated fucose incorporated into proteins released by fetal calf tests into incubation medium proved to be a marker for anti-müllerian hormone (AMH) once non-specific glycoproteins had been eliminated by partial purification. When partially purified incubation medium from fetal calf teste s was fractionated by gel filtration, sucrose density gradient sedimentation or preparative electrofocusing, a single radioactive protein peak co-purified with anti-müllerian activity. Partially purified medium from bull testes--which are devoid of anti-müllerian activity--has a much lower fucose content than that derived from fetal testes. Antisera directed against 'fetal'--but not 'bull'--partially purified incubation medium, and capable of blocking anti-müllerian activity, precipitated the radioactive protein peak. The molecular weight of labelled AMH was 215,000 when determined by gel filtration and 124,000 when determined by density gradient sedimentation. By SDS-PAGE the molecular weight of labelled AMH was 123,000 and dissociation into a 72,000 subunit was demonstrated under conditions which reduce disulfide bonds.

Animals↗
PubMed1977

FSH: II. Evidence for its mediating role on testosterone secretion in hypopituitarism.

Testicular responses to administration of human chorionic gonadotrophin (HCG) in 23 hypopituitary patients were compared to responses obtained in adequate control groups and correlated to basal plasma follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels. Sixteen nonpubertal patients demonstrated a significantly diminished testosterone response (250 +/- 64 ng/100 ml, mean +/- SEM) along with low basal plasma FSH values (1.4 +/- 0.2 mU/ml) when compared to normal response (607 +/- 97 ng/100 ml) and normal FSH level (2.3 +/- 0.2 mU/ml), but with normal LH values. In 7 pubertal patients decreased testosterone responses to HCG (815 +/- 147 ng/100 ml) were observed with normal plasma FSH and LH values. Correlation between testosterone responses and FSH levels (r - 0.718, P less than 0.002) in the pre-pubertal hypopituitary patients was highly significant. No such correlation was observed between testosterone response and LH. The represent findings may a) give one explanation for the absence of response to HCG observed in some cases of hypopituitarism, b) give support to the hypothesis that FSH has a mediating role on LH-induced secretion of testosterone by the testis in human subjects.

Adolescent↗
PubMed1977

The anti-Müllerian hormone.

Müllerian regression in the male fetus is mediated by a discrete fetal testicular hormone, different from testosterone and synthetized by Sertoli cells. Secretion of AMH begins shortly after testicular differentiation and lasts into the perinatal period; however, the müllerian duct is responsive to AMH only during a short "critical" period at the end of the ambisexual stage. Species-specificity has not been demonstrated in mammals, but avian müllerian ducts do not respond to mammalian AMH, although the mammalian müllerian ducts to respond to avian AMH. Investigations concerning the biochemical nature of AMH have been carried out on incubation media of calf fetal testes. Anti-müllerian activity of the incubation medium is not affected by dialysis, is enhanced by concentration by ultrafiltration and is not correlated with the testosterone content of the medium. Gel filtration of the incubation medium on Sephadex G 200 and Biogel A-5m indicates that the anti-müllerian hormone is a protein of relatively high molecular weight, between 200,000 and 320,000 daltons.

Animals↗
PubMed1976

Anti-Müllerian hormone: estimation of molecular weight by gel filtration.

Incubation medium of calf fetal testes was submitted to gel filtration on Sephades G 200 and Bio-Gel A-5 M, IN ORDER TO DETERMINE THE MOLECULAR WEIGHT OF THE ANTIMULLERIAN HORmone (A.M.H.) RESPONSIBLE FOR THE REGRESSION OF MULLERIAN DUCTS IN MALE FETUSES. Results from both series of experiments indicate a molecular weight in the range between 200,000 and 295,000 daltons, even in the presence of high concentration of a reducing agent.

Animals↗